Update the .c files that depend on these APIs.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The might_sleep_if() assertions in __pm_runtime_idle(),
__pm_runtime_suspend() and __pm_runtime_resume() may generate
false-positive warnings in some situations. For example, that
happens if a nested pm_runtime_get_sync()/pm_runtime_put() pair
is executed with disabled interrupts within an outer
pm_runtime_get_sync()/pm_runtime_put() section for the same device.
[Generally, pm_runtime_get_sync() may sleep, so it should not be
called with disabled interrupts, but in this particular case the
previous pm_runtime_get_sync() guarantees that the device will not
be suspended, so the inner pm_runtime_get_sync() will return
immediately after incrementing the device's usage counter.]
That started to happen in the i915 driver in 4.10-rc, leading to
the following splat:
BUG: sleeping function called from invalid context at drivers/base/power/runtime.c:1032
in_atomic(): 1, irqs_disabled(): 0, pid: 1500, name: Xorg
1 lock held by Xorg/1500:
#0: (&dev->struct_mutex){+.+.+.}, at:
[<ffffffffa0680c13>] i915_mutex_lock_interruptible+0x43/0x140 [i915]
CPU: 0 PID: 1500 Comm: Xorg Not tainted
Call Trace:
dump_stack+0x85/0xc2
___might_sleep+0x196/0x260
__might_sleep+0x53/0xb0
__pm_runtime_resume+0x7a/0x90
intel_runtime_pm_get+0x25/0x90 [i915]
aliasing_gtt_bind_vma+0xaa/0xf0 [i915]
i915_vma_bind+0xaf/0x1e0 [i915]
i915_gem_execbuffer_relocate_entry+0x513/0x6f0 [i915]
i915_gem_execbuffer_relocate_vma.isra.34+0x188/0x250 [i915]
? trace_hardirqs_on+0xd/0x10
? i915_gem_execbuffer_reserve_vma.isra.31+0x152/0x1f0 [i915]
? i915_gem_execbuffer_reserve.isra.32+0x372/0x3a0 [i915]
i915_gem_do_execbuffer.isra.38+0xa70/0x1a40 [i915]
? __might_fault+0x4e/0xb0
i915_gem_execbuffer2+0xc5/0x260 [i915]
? __might_fault+0x4e/0xb0
drm_ioctl+0x206/0x450 [drm]
? i915_gem_execbuffer+0x340/0x340 [i915]
? __fget+0x5/0x200
do_vfs_ioctl+0x91/0x6f0
? __fget+0x111/0x200
? __fget+0x5/0x200
SyS_ioctl+0x79/0x90
entry_SYSCALL_64_fastpath+0x23/0xc6
even though the code triggering it is correct.
Unfortunately, the might_sleep_if() assertions in question are
too coarse-grained to cover such cases correctly, so make them
a bit less sensitive in order to avoid the false-positives.
Reported-and-tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Here's the new driver core patches for 4.10-rc1.
Big thing here is the nice addition of "functional dependencies" to the
driver core. The idea has been talked about for a very long time, great
job to Rafael for stepping up and implementing it. It's been tested for
longer than the 4.9-rc1 date, we held off on merging it earlier in order
to feel more comfortable about it.
Other than that, it's just a handful of small other patches, some good
cleanups to the mess that is the firmware class code, and we have a test
driver for the deferred probe logic.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here's the new driver core patches for 4.10-rc1.
Big thing here is the nice addition of "functional dependencies" to
the driver core. The idea has been talked about for a very long time,
great job to Rafael for stepping up and implementing it. It's been
tested for longer than the 4.9-rc1 date, we held off on merging it
earlier in order to feel more comfortable about it.
Other than that, it's just a handful of small other patches, some good
cleanups to the mess that is the firmware class code, and we have a
test driver for the deferred probe logic.
All of these have been in linux-next for a while with no reported
issues"
* tag 'driver-core-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (30 commits)
firmware: Correct handling of fw_state_wait() return value
driver core: Silence device links sphinx warning
firmware: remove warning at documentation generation time
drivers: base: dma-mapping: Fix typo in dmam_alloc_non_coherent comments
driver core: test_async: fix up typo found by 0-day
firmware: move fw_state_is_done() into UHM section
firmware: do not use fw_lock for fw_state protection
firmware: drop bit ops in favor of simple state machine
firmware: refactor loading status
firmware: fix usermode helper fallback loading
driver core: firmware_class: convert to use class_groups
driver core: devcoredump: convert to use class_groups
driver core: class: add class_groups support
kernfs: Declare two local data structures static
driver-core: fix platform_no_drv_owner.cocci warnings
drivers/base/memory.c: Remove unused 'first_page' variable
driver core: add CLASS_ATTR_WO()
drivers: base: cacheinfo: support DT overrides for cache properties
drivers: base: cacheinfo: add pr_fmt logging
drivers: base: cacheinfo: fix boot error message when acpi is enabled
...
I noticed some wakeirq flakeyness with consumer drivers not using
autosuspend. For drivers not using autosuspend, the wakeirq may never
get unmasked in rpm_suspend() because of irq desc->depth.
We are configuring dedicated wakeirqs to start with IRQ_NOAUTOEN as we
naturally don't want them running until rpm_suspend() is called.
However, when a consumer driver initially calls pm_runtime_get(), we
now wrongly start with disable_irq_nosync() call on the dedicated
wakeirq that is disabled to start with.
This causes desc->depth to toggle between 1 and 2 instead of the usual
0 and 1. This can prevent enable_irq() from unmasking the wakeirq as
that only happens at desc->depth 1.
This does not necessarily show up with drivers using autosuspend as
there is time for disable_irq_nosync() before rpm_suspend() gets called
after the autosuspend timeout.
Let's fix the issue by adding wirq->status that lazily gets set on
the first rpm_suspend(). We also need PM runtime core private functions
for dev_pm_enable_wake_irq_check() and dev_pm_disable_wake_irq_check()
so we can enable the dedicated wakeirq on the first rpm_suspend().
While at it, let's also fix the comments for dev_pm_enable_wake_irq()
and dev_pm_disable_wake_irq(). Those can still be used by the consumer
drivers as needed because the IRQ core manages the interrupt usecount
for us.
Fixes: 4990d4fe32 (PM / Wakeirq: Add automated device wake IRQ handling)
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When the pm_runtime_force_suspend|resume() helpers were invented, we still
had CONFIG_PM_RUNTIME and CONFIG_PM_SLEEP as separate Kconfig options.
To make sure these helpers worked for all combinations and without
introducing too much of complexity, the device was always resumed in
pm_runtime_force_resume().
More precisely, when CONFIG_PM_SLEEP was set and CONFIG_PM_RUNTIME was
unset, we needed to resume the device as the subsystem/driver couldn't
rely on using runtime PM to do it.
As the CONFIG_PM_RUNTIME option was merged into CONFIG_PM a while ago, it
removed this combination, of using CONFIG_PM_SLEEP without the earlier
CONFIG_PM_RUNTIME.
For this reason we can now rely on the subsystem/driver to use runtime PM
to resume the device, instead of forcing that to be done in all cases. In
other words, let's defer the runtime resume to a later point when it's
actually needed.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When resuming a device in __pm_runtime_set_status(), the prerequisite is
that its parent must already be active, else an error code is returned and
the device's status remains suspended.
When suspending a device there is no similar constraints being validated.
Let's change this to make the behaviour consistent, by not allowing to
suspend a device with an active child, unless it has been explicitly set to
ignore its children.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If the device has no links to suppliers that should be used for
runtime PM (links with DEVICE_LINK_PM_RUNTIME set), there is no
reason to walk the list of suppliers for that device during
runtime suspend and resume.
Add a simple mechanism to detect that case and possibly avoid the
extra unnecessary overhead.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Modify the runtime PM framework to use device links to ensure that
supplier devices will not be suspended if any of their consumer
devices are active.
The idea is to reference count suppliers on the consumer's resume
and drop references to them on its suspend. The information on
whether or not the supplier has been reference counted by the
consumer's (runtime) resume is stored in a new field (rpm_active)
in the link object for each link.
It may be necessary to clean up those references when the
supplier is unbinding and that's why the links whose status is
DEVICE_LINK_SUPPLIER_UNBIND are skipped by the runtime suspend
and resume code.
The above means that if the consumer device is probed in the
runtime-active state, the supplier has to be resumed and reference
counted by device_link_add() so the code works as expected on its
(runtime) suspend. There is a new flag, DEVICE_LINK_RPM_ACTIVE,
to tell device_link_add() about that (in which case the caller
is responsible for making sure that the consumer really will
be runtime-active when runtime PM is enabled for it).
The other new link flag, DEVICE_LINK_PM_RUNTIME, tells the core
whether or not the link should be used for runtime PM at all.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The exported function pm_children_suspended() has only one caller, which is
the runtime PM internal function, rpm_check_suspend_allowed().
Let's clean-up this code, by removing pm_children_suspended() altogether
and instead do the one-liner check directly in rpm_check_suspend_allowed().
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Further testing with false negatives suppressed by commit 293e2421fe
("rcu: Remove superfluous versions of rcu_read_lock_sched_held()")
identified a few more unprotected uses of RCU from the idle loop.
Because RCU actively ignores idle-loop code (for energy-efficiency
reasons, among other things), using RCU from the idle loop can result
in too-short grace periods, in turn resulting in arbitrary misbehavior.
The affected function is rpm_suspend().
The resulting lockdep-RCU splat is as follows:
------------------------------------------------------------------------
Warning from omap3
===============================
[ INFO: suspicious RCU usage. ]
4.6.0-rc5-next-20160426+ #1112 Not tainted
-------------------------------
include/trace/events/rpm.h:63 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
RCU used illegally from extended quiescent state!
1 lock held by swapper/0/0:
#0: (&(&dev->power.lock)->rlock){-.-...}, at: [<c052ee24>] __pm_runtime_suspend+0x54/0x84
stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1112
Hardware name: Generic OMAP36xx (Flattened Device Tree)
[<c0110308>] (unwind_backtrace) from [<c010c3a8>] (show_stack+0x10/0x14)
[<c010c3a8>] (show_stack) from [<c047fec8>] (dump_stack+0xb0/0xe4)
[<c047fec8>] (dump_stack) from [<c052d7b4>] (rpm_suspend+0x604/0x7e4)
[<c052d7b4>] (rpm_suspend) from [<c052ee34>] (__pm_runtime_suspend+0x64/0x84)
[<c052ee34>] (__pm_runtime_suspend) from [<c04bf3bc>] (omap2_gpio_prepare_for_idle+0x5c/0x70)
[<c04bf3bc>] (omap2_gpio_prepare_for_idle) from [<c01255e8>] (omap_sram_idle+0x140/0x244)
[<c01255e8>] (omap_sram_idle) from [<c0126b48>] (omap3_enter_idle_bm+0xfc/0x1ec)
[<c0126b48>] (omap3_enter_idle_bm) from [<c0601db8>] (cpuidle_enter_state+0x80/0x3d4)
[<c0601db8>] (cpuidle_enter_state) from [<c0183c74>] (cpu_startup_entry+0x198/0x3a0)
[<c0183c74>] (cpu_startup_entry) from [<c0b00c0c>] (start_kernel+0x354/0x3c8)
[<c0b00c0c>] (start_kernel) from [<8000807c>] (0x8000807c)
------------------------------------------------------------------------
Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit appends a few _rcuidle suffixes to fix the following
RCU-used-from-idle bug:
> ===============================
> [ INFO: suspicious RCU usage. ]
> 4.6.0-rc5-next-20160426+ #1116 Not tainted
> -------------------------------
> include/trace/events/rpm.h:95 suspicious rcu_dereference_check() usage!
>
> other info that might help us debug this:
>
>
> RCU used illegally from idle CPU!
> rcu_scheduler_active = 1, debug_locks = 0
> RCU used illegally from extended quiescent state!
> 1 lock held by swapper/0/0:
> #0: (&(&dev->power.lock)->rlock){-.-...}, at: [<c052cc2c>] __rpm_callback+0x58/0x60
>
> stack backtrace:
> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1116
> Hardware name: Generic OMAP36xx (Flattened Device Tree)
> [<c0110290>] (unwind_backtrace) from [<c010c3a8>] (show_stack+0x10/0x14)
> [<c010c3a8>] (show_stack) from [<c047fd68>] (dump_stack+0xb0/0xe4)
> [<c047fd68>] (dump_stack) from [<c052d5d0>] (rpm_suspend+0x580/0x768)
> [<c052d5d0>] (rpm_suspend) from [<c052ec58>] (__pm_runtime_suspend+0x64/0x84)
> [<c052ec58>] (__pm_runtime_suspend) from [<c04bf25c>] (omap2_gpio_prepare_for_idle+0x5c/0x70)
> [<c04bf25c>] (omap2_gpio_prepare_for_idle) from [<c0125568>] (omap_sram_idle+0x140/0x244)
> [<c0125568>] (omap_sram_idle) from [<c01269dc>] (omap3_enter_idle_bm+0xfc/0x1ec)
> [<c01269dc>] (omap3_enter_idle_bm) from [<c0601bdc>] (cpuidle_enter_state+0x80/0x3d4)
> [<c0601bdc>] (cpuidle_enter_state) from [<c0183b08>] (cpu_startup_entry+0x198/0x3a0)
> [<c0183b08>] (cpu_startup_entry) from [<c0b00c0c>] (start_kernel+0x354/0x3c8)
> [<c0b00c0c>] (start_kernel) from [<8000807c>] (0x8000807c)
In the immortal words of Steven Rostedt, "*Whack* *Whack* *Whack*!!!"
Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
WhACKED-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-core:
PM / runtime: Asynchronous "idle" in pm_runtime_allow()
PM / runtime: print error when activating a child to unactive parent
* pm-clk:
PM / clk: Add support for adding a specific clock from device-tree
PM / clk: export symbols for existing pm_clk_<...> API fcns
* pm-domains:
PM / Domains: Convert pm_genpd_init() to return an error code
PM / Domains: Stop/start devices during system PM suspend/resume in genpd
PM / Domains: Allow runtime PM during system PM phases
PM / Runtime: Avoid resuming devices again in pm_runtime_force_resume()
PM / Domains: Remove redundant pm_request_idle() call in genpd
PM / Domains: Remove redundant wrapper functions for system PM
PM / Domains: Allow genpd to power on during system PM phases
* pm-pci:
PCI / PM: check all fields in pci_set_platform_pm()
Arjan reports that it takes a relatively long time to enable runtime
PM for multiple devices at system startup, because all writes to the
"control" attribute in sysfs are handled synchronously and if the
device is suspended as a result of the write, it will block until
that operation is complete.
That may be avoided by passing the RPM_ASYNC flag to rpm_idle()
in pm_runtime_allow() which will make it execute the device's
"idle" callback asynchronously, so writes to "control" changing
it from "on" to "auto" will return without waiting.
Reported-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
The code currently silently bails out with -EBUSY if you try to
activate a child to an inactive parent.
This typically happens when you have a runtime suspended parent
and runtime resume your child, but forgot to set .ignore_children
on the parent to true with pm_suspend_ignore_children(dev).
Silently ignoring this error is not good as it gives rise to
other strange behaviour like double-resume of devices after
silently bailing out of the .runtime_resume() callback.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If the runtime PM status of the device isn't RPM_SUSPENDED, prevent the
pm_runtime_force_resume() from invoking the ->runtime_resume() callback
for the device, as it's not the expected behaviour from the subsystem/driver.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
As pm_runtime_set_active() may fail because the device's parent isn't
active, we can end up executing the ->runtime_resume() callback for the
device when it isn't allowed.
Fix this by invoking pm_runtime_set_active() before running the callback
and let's also deal with the error code.
Fixes: 37f204164d (PM: Add pm_runtime_suspend|resume_force functions)
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: 3.15+ <stable@vger.kernel.org> # 3.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Introduce a new runtime PM function, pm_runtime_get_if_in_use(),
that will increment the device's runtime PM usage counter and
return 1 if its status is RPM_ACTIVE and its usage counter
is greater than 0 at the same time (0 will be returned otherwise).
This is useful for things that should only be done if the device
is active (from the runtime PM perspective) and used by somebody
(as indicated by the usage counter) already and they are not worth
bothering otherwise.
Requested-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are two common expectations among several subsystems/drivers that
deploys runtime PM support, but which isn't met by the driver core.
Expectation 1)
At ->probe() the subsystem/driver expects the runtime PM status of the
device to be RPM_SUSPENDED, which is the initial status being assigned at
device registration.
This expectation is especially common among some of those subsystems/
drivers that manages devices with an attached PM domain, as those requires
the ->runtime_resume() callback at the PM domain level to be invoked
during ->probe().
Moreover these subsystems/drivers entirely relies on runtime PM resources
being managed at the PM domain level, thus don't implement their own set
of runtime PM callbacks.
These are two scenarios that suffers from this unmet expectation.
i) A failed ->probe() sequence requests probe deferral:
->probe()
...
pm_runtime_enable()
pm_runtime_get_sync()
...
err:
pm_runtime_put()
pm_runtime_disable()
...
As there are no guarantees that such sequence turns the runtime PM status
of the device into RPM_SUSPENDED, the re-trying ->probe() may start with
the status in RPM_ACTIVE.
In such case the runtime PM core won't invoke the ->runtime_resume()
callback because of a pm_runtime_get_sync(), as it considers the device to
be already runtime resumed.
ii) A driver re-bind sequence:
At driver unbind, the subsystem/driver's >remove() callback invokes a
sequence of runtime PM APIs, to undo actions during ->probe() and to put
the device into low power state.
->remove()
...
pm_runtime_put()
pm_runtime_disable()
...
Similar as in the failing ->probe() case, this sequence don't guarantee
the runtime PM status of the device to turn into RPM_SUSPENDED.
Trying to re-bind the driver thus causes the same issue as when re-trying
->probe(), in the probe deferral scenario.
Expectation 2)
Drivers that invokes the pm_runtime_irq_safe() API during ->probe(),
triggers the runtime PM core to increase the usage count for the device's
parent and permanently make it runtime resumed.
The usage count is only dropped at device removal, which also allows it to
be runtime suspended again.
A re-trying ->probe() repeats the call to pm_runtime_irq_safe() and thus
once more triggers the usage count of the device's parent to be increased.
This leads to not only an imbalance issue of the usage count of the
device's parent, but also to keep it runtime resumed permanently even if
->probe() fails.
To address these issues, let's change the policy of the driver core to
meet these expectations. More precisely, at ->probe() failures and driver
unbind, restore the initial states of runtime PM.
Although to still allow subsystem's to control PM for devices that doesn't
->probe() successfully, don't restore the initial states unless runtime PM
is disabled.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Turns out we can automate the handling for the device_may_wakeup()
quite a bit by using the kernel wakeup source list as suggested
by Rafael J. Wysocki <rjw@rjwysocki.net>.
And as some hardware has separate dedicated wake-up interrupt
in addition to the IO interrupt, we can automate the handling by
adding a generic threaded interrupt handler that just calls the
device PM runtime to wake up the device.
This allows dropping code from device drivers as we currently
are doing it in multiple ways, and often wrong.
For most drivers, we should be able to drop the following
boilerplate code from runtime_suspend and runtime_resume
functions:
...
device_init_wakeup(dev, true);
...
if (device_may_wakeup(dev))
enable_irq_wake(irq);
...
if (device_may_wakeup(dev))
disable_irq_wake(irq);
...
device_init_wakeup(dev, false);
...
We can replace it with just the following init and exit
time code:
...
device_init_wakeup(dev, true);
dev_pm_set_wake_irq(dev, irq);
...
dev_pm_clear_wake_irq(dev);
device_init_wakeup(dev, false);
...
And for hardware with dedicated wake-up interrupts:
...
device_init_wakeup(dev, true);
dev_pm_set_dedicated_wake_irq(dev, irq);
...
dev_pm_clear_wake_irq(dev);
device_init_wakeup(dev, false);
...
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If we don't update last_busy in rpm_resume, devices can go back
to sleep immediately after resume. This happens at least in
cases where the device has been powered off and does not have
any interrupt pending until there's something in the FIFO.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
After commit b2b49ccbdd (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so quite a few
depend on CONFIG_PM or even may be dropped entirely in some cases.
Replace CONFIG_PM_RUNTIME with CONFIG_PM in the PM core code.
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM uses three separate functions to fetch RPM callbacks.
These functions uses quite complicated macro in their body.
The patch replaces these routines with one small macro and
one helper function.
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch provides two new runtime PM helper functions which intend to
be used from system suspend/resume callbacks, to make sure devices are
put into low power state during system suspend and brought back to full
power at system resume.
The prerequisite is to have all levels of a device's runtime PM
callbacks to be defined through the SET_PM_RUNTIME_PM_OPS macro, which
means these are available for CONFIG_PM.
By using the new runtime PM helper functions especially the two
scenarios below will be addressed.
1) The PM core prevents .runtime_suspend callbacks from being invoked
during system suspend. That means even for a runtime PM centric
subsystem and driver, the device needs to be put into low power state
from a system suspend callback. Otherwise it may very well be left in
full power state (runtime resumed) while the system is suspended. By
using the new helper functions, we make sure to walk the hierarchy of
a device's power domain, subsystem and driver.
2) Subsystems and drivers need to cope with all the combinations of
CONFIG_PM_SLEEP and CONFIG_PM_RUNTIME. The two new helper functions
smothly addresses this.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
While fetching the proper runtime PM callback, we walk the hierarchy of
device's power domains, subsystems and drivers.
This is common for rpm_suspend(), rpm_idle() and rpm_resume(). Let's
clean up the code by using a macro that handles this.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
For devices which don't have a .runtime_idle() callback or if it
returns 0, rpm_idle() will end up in triggering a call to
rpm_suspend(), thus trying to carry out a runtime suspend directly
from runtime_idle().
In the above situation we want to respect devices which has enabled
autosuspend, we therfore append the flag sent to rpm_suspend with
RPM_AUTO.
Do note that drivers still needs to update the device last busy mark,
to control the delay for this circumstance.
Updated runtime PM documentation accordingly.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The "runtime idle" helper routine, rpm_idle(), currently ignores
return values from .runtime_idle() callbacks executed by it.
However, it turns out that many subsystems use
pm_generic_runtime_idle() which checks the return value of the
driver's callback and executes pm_runtime_suspend() for the device
unless that value is not 0. If that logic is moved to rpm_idle()
instead, pm_generic_runtime_idle() can be dropped and its users
will not need any .runtime_idle() callbacks any more.
Moreover, the PCI, SCSI, and SATA subsystems' .runtime_idle()
routines, pci_pm_runtime_idle(), scsi_runtime_idle(), and
ata_port_runtime_idle(), respectively, as well as a few drivers'
ones may be simplified if rpm_idle() calls rpm_suspend() after 0 has
been returned by the .runtime_idle() callback executed by it.
To reduce overall code bloat, make the changes described above.
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
For irq safe devices return the runtime reference for the parent
by using the asyncronous runtime PM API. Thus we don't have to
wait for it to become idle|suspended. Instead we can move on and
handle the next device in queue.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Apply the introduced memalloc_noio_save() and memalloc_noio_restore() to
force memory allocation with no I/O during runtime_resume/runtime_suspend
callback on device with the flag of 'memalloc_noio' set.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Decotigny <david.decotigny@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oneukum@suse.de>
Cc: Jiri Kosina <jiri.kosina@suse.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce the flag memalloc_noio in 'struct dev_pm_info' to help PM core
to teach mm not allocating memory with GFP_KERNEL flag for avoiding
probable deadlock.
As explained in the comment, any GFP_KERNEL allocation inside
runtime_resume() or runtime_suspend() on any one of device in the path
from one block or network device to the root device in the device tree
may cause deadlock, the introduced pm_runtime_set_memalloc_noio() sets
or clears the flag on device in the path recursively.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oneukum@suse.de>
Cc: Jiri Kosina <jiri.kosina@suse.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Decotigny <david.decotigny@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are several drivers where the return value of
pm_runtime_get_sync() is used to decide whether or not it is safe to
access hardware and that don't provide .suspend() callbacks for system
suspend (but may use late/noirq callbacks.) If such a driver happens
to call pm_runtime_get_sync() during system suspend, after the core
has disabled runtime PM, it will get the error code and will decide
that the hardware should not be accessed, although this may be a wrong
conclusion, depending on the state of the device when runtime PM was
disabled.
Drivers might work around this problem by using a test like:
ret = pm_runtime_get_sync(dev);
if (!ret || (ret == -EACCES && driver_private_data(dev)->suspended)) {
/* access hardware */
}
where driver_private_data(dev)->suspended is a flag set by the
driver's .suspend() method (that would have to be added for this
purpose). However, that potentially would need to be done by multiple
drivers which means quite a lot of duplicated code and bloat.
To avoid that we can use the observation that the core sets
dev->power.is_suspended before disabling runtime PM and use that
instead of the driver's private flag. Still, potentially many drivers
would need to repeat that same check in quite a few places, so it's
better to let the core do it.
Then we can be a bit smarter and check whether or not runtime PM was
disabled by the core only (disable_depth == 1) or by someone else in
addition to the core (disable_depth > 1). In the former case
rpm_resume() can return 1 if the runtime PM status is RPM_ACTIVE,
because it means the device was active when the core disabled runtime
PM. In the latter case it should still return -EACCES, because it
isn't clear why runtime PM has been disabled.
Tested on AM3730/Beagle-xM where a wakeup IRQ firing during the late
suspend phase triggers runtime PM activity in the I2C driver since the
wakeup IRQ is on an I2C-connected PMIC.
[rjw: Modified whitespace to follow the file's convention.]
Signed-off-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
If __dev_pm_qos_read_value(dev) returns a negative value,
rpm_suspend() should return -EPERM for dev even if its
power.no_callbacks flag is set. For this to happen, the device's
power.no_callbacks flag has to be checked after the PM QoS check,
so move the PM QoS check to rpm_check_suspend_allowed() (this will
make it cover idle notifications as well as runtime suspend too).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@vger.kernel.org
The power.deferred_resume can only be set if the runtime PM status
of device is RPM_SUSPENDING and it should be cleared after its
status has been changed, regardless of whether or not the runtime
suspend has been successful. However, it only is cleared on
suspend failure, while it may remain set on successful suspend and
is happily leaked to rpm_resume() executed in that case.
That shouldn't happen, so if power.deferred_resume is set in
rpm_suspend() after the status has been changed to RPM_SUSPENDED,
clear it before calling rpm_resume(). Then, it doesn't need to be
cleared before changing the status to RPM_SUSPENDING any more,
because it's always cleared after the status has been changed to
either RPM_SUSPENDED (on success) or RPM_ACTIVE (on failure).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@vger.kernel.org
For devices whose power.no_callbacks flag is set, rpm_resume()
should return 1 if the device's parent is already active, so that
the callers of pm_runtime_get() don't think that they have to wait
for the device to resume (asynchronously) in that case (the core
won't queue up an asynchronous resume in that case, so there's
nothing to wait for anyway).
Modify the code accordingly (and make sure that an idle notification
will be queued up on success, even if 1 is to be returned).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@vger.kernel.org
After the previous changes in default_stop_ok() and
default_power_down_ok() for PM domains, there are two fields in
struct dev_pm_info that aren't necessary any more, suspend_time
and max_time_suspended_ns.
Remove those fields along with all of the code that accesses them,
which simplifies the runtime PM framework quite a bit.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1535) fixes a bug in the runtime PM core. When a
runtime suspend attempt completes, whether successfully or not, the
device's power.wait_queue is supposed to be signalled. But this
doesn't happen in the failure pathway of rpm_suspend() when another
autosuspend attempt is rescheduled. As a result, a task can get stuck
indefinitely on the wait queue (I have seen this happen in testing).
The patch fixes the problem by moving the wake_up_all() call up near
the start of the failure code.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Make the PM core execute driver PM callbacks directly if the
corresponding subsystem callbacks are not present.
There are three reasons for doing that. First, it reflects the
behavior of drivers/base/dd.c:really_probe() that runs the driver's
.probe() callback directly if the bus type's one is not defined, so
this change will remove one arbitrary difference between the PM core
and the remaining parts of the driver core. Second, it will allow
some subsystems, whose PM callbacks don't do anything except for
executing driver callbacks, to be simplified quite a bit by removing
those "forward-only" callbacks. Finally, it will allow us to remove
one level of indirection in the system suspend and resume code paths
where it is not necessary, which is going to lead to less debug noise
with initcall_debug passed in the kernel command line (messages won't
be printed for driverless devices whose subsystems don't provide
PM callbacks among other things).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Make the runtime PM core use device PM QoS constraints to check if
it is allowed to suspend a given device, so that an error code is
returned if the device's own PM QoS constraint is negative or one of
its children has already been suspended for too long. If this is
not the case, the maximum estimated time the device is allowed to be
suspended, computed as the minimum of the device's PM QoS constraint
and the PM QoS constraints of its children (reduced by the difference
between the current time and their suspend times) is stored in a new
device's PM field power.max_time_suspended_ns that can be used by
the device's subsystem or PM domain to decide whether or not to put
the device into lower-power (and presumably higher-latency) states
later (if the constraint is 0, which means "no constraint", the
power.max_time_suspended_ns is set to -1).
Additionally, the time of execution of the subsystem-level
.runtime_suspend() callback for the device is recorded in the new
power.suspend_time field for later use by the device's subsystem or
PM domain along with power.max_time_suspended_ns (it also is used
by the core code when the device's parent is suspended).
Introduce a new helper function,
pm_runtime_update_max_time_suspended(), allowing subsystems and PM
domains (or device drivers) to update the power.max_time_suspended_ns
field, for example after changing the power state of a suspended
device.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
Originally, the runtime PM core would send an idle notification
whenever a suspend attempt failed. The idle callback routine could
then schedule a delayed suspend for some time later.
However this behavior was changed by commit
f71648d73c (PM / Runtime: Remove idle
notification after failing suspend). No notifications were sent, and
there was no clear mechanism to retry failed suspends.
This caused problems for the usbhid driver, because it fails
autosuspend attempts as long as a key is being held down. Therefore
this patch (as1492) adds a mechanism for retrying failed
autosuspends. If the callback routine updates the last_busy field so
that the next autosuspend expiration time is in the future, the
autosuspend will automatically be rescheduled.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Henrik Rydberg <rydberg@euromail.se>
Cc: <stable@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
With delta type being int, its value is made zero
for all values of now > 0x80000000.
Hence fixing it.
Signed-off-by: venu byravarasu <vbyravarasu@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Most of these files were implicitly getting EXPORT_SYMBOL via
device.h which was including module.h, but that path will be broken
soon.
[ with input from Stephen Rothwell <sfr@canb.auug.org.au> ]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
If .runtime_suspend() returns -EAGAIN or -EBUSY, the device should
still be in ACTIVE state, so it is not necessary to send an idle
notification to its parent. If .runtime_suspend() returns other
fatal failure, it doesn't make sense to send idle notification to
its parent.
Skip parent idle notification when failure is returned from
.runtime_suspend() and update comments in rpm_suspend() to reflect
that change.
[rjw: Modified the subject and changelog slightly.]
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch fix kerneldoc comments for rpm_suspend():
- 'Cancel a pending idle notification' should be put before, also
should be changed to 'Cancel a pending idle notification,
autosuspend or suspend'.
- idle notification for the device after succeeding suspend has
been removed, so update the comment accordingly.
[rjw: Modified the subject and changelog slightly.]
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch replaces dev_dbg with trace_rpm_* inside
the three important functions:
rpm_idle
rpm_suspend
rpm_resume
Trace points have the below advantages compared with dev_dbg:
- trace points include much runtime information(such as
running cpu, current task, ...)
- most of linux distributions may disable "verbose debug"
driver debug compile switch, so it is very difficult to
report/debug runtime pm related problems from distribution
users without this kind of debug information.
- for upstream kernel users, enableing the debug switch will
produce many useless "rpm_resume" output, and it is very noise.
- dev_dbg inside rpm_suspend/rpm_resume may have some effects
on runtime pm behaviour of console devicer
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The rpm_suspend() and rpm_resume() routines execute subsystem or PM
domain callbacks under power.lock if power.irq_safe is set for the
given device. This is inconsistent with that rpm_idle() does after
commit 02b2677 (PM / Runtime: Allow _put_sync() from
interrupts-disabled context) and is problematic for subsystems and PM
domains wanting to use power.lock for synchronization in their
runtime PM callbacks.
This change requires the code checking if the device's runtime PM
status is RPM_SUSPENDING or RPM_RESUMING to be modified too, to take
the power.irq_safe set case into account (that code wasn't reachable
before with power.irq_safe set, because it's executed with the
device's power.lock held).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Some of the entry points to pm runtime are not safe to
call in atomic context unless pm_runtime_irq_safe() has
been called. Inspecting the code, it is not immediately
obvious that the functions sleep at all, as they run
inside a spin_lock_irqsave, but under some conditions
they can drop the lock and turn on irqs.
If a driver incorrectly calls the pm_runtime apis, it can
cause sleeping and irq processing when it expects to stay
in atomic context.
Add might_sleep_if to the majority of the __pm_runtime_* entry points
to enforce correct usage.
Add pm_runtime_put_sync_autosuspend to the list of
functions that can be called in atomic context.
Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Currently the use of pm_runtime_put_sync() is not safe from
interrupts-disabled context because rpm_idle() will release the
spinlock and enable interrupts for the idle callbacks. This enables
interrupts during a time where interrupts were expected to be
disabled, and can have strange side effects on drivers that expected
interrupts to be disabled.
This is not a bug since the documentation clearly states that only
_put_sync_suspend() is safe in IRQ-safe mode.
However, pm_runtime_put_sync() could be made safe when in IRQ-safe
mode by releasing the spinlock but not re-enabling interrupts, which
is what this patch aims to do.
Problem was found when using some buggy drivers that set
pm_runtime_irq_safe() and used _put_sync() in interrupts-disabled
context.
Reported-by: Colin Cross <ccross@google.com>
Tested-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
dev->power.deferred_resume is used as a bool typically, so change
one assignment to false from 0, like other places.
Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
The runtime PM documentation and kerneldoc comments sometimes spell
"runtime" with a dash (i.e. "run-time"). Replace all of those
instances with "runtime" to make the naming consistent.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Some callers of pm_runtime_get_sync() and other runtime PM helper
functions, scsi_autopm_get_host() and scsi_autopm_get_device() in
particular, need to distinguish error codes returned when runtime PM
is disabled (i.e. power.disable_depth is nonzero for the given
device) from error codes returned in other situations. For this
reason, make the runtime PM helper functions return -EACCES when
power.disable_depth is nonzero and ensure that this error code
won't be returned by them in any other circumstances. Modify
scsi_autopm_get_host() and scsi_autopm_get_device() to check the
error code returned by pm_runtime_get_sync() and ignore -EACCES.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The naming convention used by commit 7538e3db6e015e890825fbd9f86599b
(PM: Add support for device power domains), which introduced the
struct dev_power_domain type for representing device power domains,
evidently confuses some developers who tend to think that objects
of this type must correspond to "power domains" as defined by
hardware, which is not the case. Namely, at the kernel level, a
struct dev_power_domain object can represent arbitrary set of devices
that are mutually dependent power management-wise and need not belong
to one hardware power domain. To avoid that confusion, rename struct
dev_power_domain to struct dev_pm_domain and rename the related
pointers in struct device and struct pm_clk_notifier_block from
pwr_domain to pm_domain.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
Change the PM core's behavior related to power domains in such a way
that, if a power domain is defined for a given device, its callbacks
will be executed instead of and not in addition to the device
subsystem's PM callbacks.
The idea behind the initial implementation of power domains handling
by the PM core was that power domain callbacks would be executed in
addition to subsystem callbacks, so that it would be possible to
extend the subsystem callbacks by using power domains. It turns out,
however, that this wouldn't be really convenient in some important
situations.
For example, there are systems in which power can only be removed
from entire power domains. On those systems it is not desirable to
execute device drivers' PM callbacks until it is known that power is
going to be removed from the devices in question, which means that
they should be executed by power domain callbacks rather then by
subsystem (e.g. bus type) PM callbacks, because subsystems generally
have no information about what devices belong to which power domain.
Thus, for instance, if the bus type in question is the platform bus
type, its PM callbacks generally should not be called in addition to
power domain callbacks, because they run device drivers' callbacks
unconditionally if defined.
While in principle the default subsystem PM callbacks, or a subset of
them, may be replaced with different functions, it doesn't seem
correct to do so, because that would change the subsystem's behavior
with respect to all devices in the system, regardless of whether or
not they belong to any power domains. Thus, the only remaining
option is to make power domain callbacks take precedence over
subsystem callbacks.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Kevin Hilman <khilman@ti.com>
The code handling system-wide power transitions (eg. suspend-to-RAM)
can in theory execute callbacks provided by the device's bus type,
device type and class in each phase of the power transition. In
turn, the runtime PM core code only calls one of those callbacks at
a time, preferring bus type callbacks to device type or class
callbacks and device type callbacks to class callbacks.
It seems reasonable to make them both behave in the same way in that
respect. Moreover, even though a device may belong to two subsystems
(eg. bus type and device class) simultaneously, in practice power
management callbacks for system-wide power transitions are always
provided by only one of them (ie. if the bus type callbacks are
defined, the device class ones are not and vice versa). Thus it is
possible to modify the code handling system-wide power transitions
so that it follows the core runtime PM code (ie. treats the
subsystem callbacks as mutually exclusive).
On the other hand, the core runtime PM code will choose to execute,
for example, a runtime suspend callback provided by the device type
even if the bus type's struct dev_pm_ops object exists, but the
runtime_suspend pointer in it happens to be NULL. This is confusing,
because it may lead to the execution of callbacks from different
subsystems during different operations (eg. the bus type suspend
callback may be executed during runtime suspend of the device, while
the device type callback will be executed during system suspend).
Make all of the power management code treat subsystem callbacks in
a consistent way, such that:
(1) If the device's type is defined (eg. dev->type is not NULL)
and its pm pointer is not NULL, the callbacks from dev->type->pm
will be used.
(2) If dev->type is NULL or dev->type->pm is NULL, but the device's
class is defined (eg. dev->class is not NULL) and its pm pointer
is not NULL, the callbacks from dev->class->pm will be used.
(3) If dev->type is NULL or dev->type->pm is NULL and dev->class is
NULL or dev->class->pm is NULL, the callbacks from dev->bus->pm
will be used provided that both dev->bus and dev->bus->pm are
not NULL.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
Reasoning-sounds-sane-to: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
The platform bus type is often used to handle Systems-on-a-Chip (SoC)
where all devices are represented by objects of type struct
platform_device. In those cases the same "platform" device driver
may be used with multiple different system configurations, but the
actions needed to put the devices it handles into a low-power state
and back into the full-power state may depend on the design of the
given SoC. The driver, however, cannot possibly include all the
information necessary for the power management of its device on all
the systems it is used with. Moreover, the device hierarchy in its
current form also is not suitable for representing this kind of
information.
The patch below attempts to address this problem by introducing
objects of type struct dev_power_domain that can be used for
representing power domains within a SoC. Every struct
dev_power_domain object provides a sets of device power
management callbacks that can be used to perform what's needed for
device power management in addition to the operations carried out by
the device's driver and subsystem.
Namely, if a struct dev_power_domain object is pointed to by the
pwr_domain field in a struct device, the callbacks provided by its
ops member will be executed in addition to the corresponding
callbacks provided by the device's subsystem and driver during all
power transitions.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-and-acked-by: Kevin Hilman <khilman@ti.com>
This patch (as1445) fixes a bug in the runtime PM core left over from
the addition of the no_callbacks flag. If this flag is set then it is
possible for rpm_suspend() to be called in_interrupt, so when
releasing spinlocks it's important not to re-enable interrupts.
To avoid an unnecessary save-and-restore of the interrupt flag, the
patch also inlines a pm_request_idle() call.
This fixes Bugzilla #27482.
(The offending code was added in 2.6.37, so it's not necessary to apply
this to any earlier stable kernels.)
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: tim blechmann <tim@klingt.org>
CC: <stable@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1431c) makes the synchronous runtime-PM interface
suitable for use in interrupt handlers. Subsystems can call the new
pm_runtime_irq_safe() function to tell the PM core that a device's
runtime_suspend and runtime_resume callbacks should be invoked with
interrupts disabled and the spinlock held. This permits the
pm_runtime_get_sync() and the new pm_runtime_put_sync_suspend()
routines to be called from within interrupt handlers.
When a device is declared irq-safe in this way, the PM core increments
the parent's usage count, so the parent will never be runtime
suspended. This prevents difficult situations in which an irq-safe
device can't resume because it is forced to wait for its non-irq-safe
parent.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
GCC version 4.5.1 gives the following warning:
drivers/base/power/runtime.c: In function ‘rpm_check_suspend_allowed’:
drivers/base/power/runtime.c:146:25: warning: comparison between ‘enum dpm_state’ and ‘enum rpm_status’
which seems to be a typo in that dev->power.runtime_status
should be compared instead of dev->power.status.
Signed-off-by: Kevin Winchester <kjwinchester@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
For device with no_callbacks flag set, its power lock and its parent's
power lock may be held nestedly in rpm_resume, so we should take
spin_lock_nested(lock, SINGLE_DEPTH_NESTING) to acquire parent power lock
to avoid lockdep warning.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
If runtime suspend of a device fails returning -EAGAIN or -EBUSY,
which means that it's safe to try to suspend it again, the PM core
runs the runtime idle helper function for it. Unfortunately this may
lead to problems, for example for PCI devices whose drivers don't
implement the ->runtime_idle() callback, because in that case the
PCI bus type's ->runtime_idle() always calls pm_runtime_suspend()
for the given device. Then, if there's an automatic idle
notification after the driver's ->runtime_suspend() returning -EAGAIN
or -EBUSY, it will make the suspend happen again possibly causing a
busy loop to appear. To avoid that, remove the idle notification
after failing runtime suspend of a device altogether and let the
callers of pm_runtime_suspend() repeat the operation if need be.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Reduce code duplication in rpm_idle(), rpm_suspend() and rpm_resume()
by using local pointers to store callback addresses and moving some
duplicated code into a separate function.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
This patch (as1427) implements the "autosuspend" facility for runtime
PM. A few new fields are added to the dev_pm_info structure and
several new PM helper functions are defined, for telling the PM core
whether or not a device uses autosuspend, for setting the autosuspend
delay, and for marking periods of device activity.
Drivers that do not want to use autosuspend can continue using the
same helper functions as before; their behavior will not change. In
addition, drivers supporting autosuspend can also call the old helper
functions to get the old behavior.
The details are all explained in Documentation/power/runtime_pm.txt
and Documentation/ABI/testing/sysfs-devices-power.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Some devices, such as USB interfaces, cannot be power-managed
independently of their parents, i.e., they cannot be put in low power
while the parent remains at full power. This patch (as1425) creates a
new "no_callbacks" flag, which tells the PM core not to invoke the
runtime-PM callback routines for the such devices but instead to
assume that the callbacks always succeed. In addition, the
non-debugging runtime-PM sysfs attributes for the devices are removed,
since they are pretty much meaningless.
The advantage of this scheme comes not so much from avoiding the
callbacks themselves, but rather from the fact that without the need
for a process context in which to run the callbacks, more work can be
done in interrupt context.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1424) combines the various public entry points for the
runtime PM routines into three simple functions: one for idle, one for
suspend, and one for resume. A new bitflag specifies whether or not
to increment or decrement the usage_count field.
The new entry points are named __pm_runtime_idle,
__pm_runtime_suspend, and __pm_runtime_resume, to reflect that they
are trampolines. Simultaneously, the corresponding internal routines
are renamed to rpm_idle, rpm_suspend, and rpm_resume.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1423) merges the asynchronous routines
__pm_request_idle(), __pm_request_suspend(), and __pm_request_resume()
with their synchronous counterparts. The RPM_ASYNC bitflag argument
serves to indicate what sort of operation to perform.
In the course of performing this merger, it became apparent that the
various functions don't all behave consistenly with regard to error
reporting and cancellation of outstanding requests. A new routine,
rpm_check_suspend_allowed(), was written to centralize much of the
testing, and the other functions were revised to follow a simple
algorithm:
If the operation is disallowed because of the device's
settings or current state, return an error.
Cancel pending or scheduled requests of lower priority.
Schedule, queue, or perform the desired operation.
A few special cases and exceptions are noted in comments.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The "from_wq" argument in __pm_runtime_suspend() and
__pm_runtime_resume() supposedly indicates whether or not the function
was called by the PM workqueue thread, but in fact it isn't always
used this way. It really indicates whether or not the function should
return early if the requested operation is already in progress.
Along with this badly-named boolean argument, later patches in this
series will add several other boolean arguments to these functions and
others. Therefore this patch (as1422) begins the conversion process
by replacing from_wq with a bitflag argument. The same bitflags are
also used in __pm_runtime_get() and __pm_runtime_put(), where they
indicate whether or not the operation should be asynchronous.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1421) moves the PM runtime accounting subroutines up to
the beginning of runtime.c, taking them out of the middle of the
functions that do the actual work. No operational changes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Introduce struct wakeup_source for representing system wakeup sources
within the kernel and for collecting statistics related to them.
Make the recently introduced helper functions pm_wakeup_event(),
pm_stay_awake() and pm_relax() use struct wakeup_source objects
internally, so that wakeup statistics associated with wakeup devices
can be collected and reported in a consistent way (the definition of
pm_relax() is changed, which is harmless, because this function is
not called directly by anyone yet). Introduce new wakeup-related
sysfs device attributes in /sys/devices/.../power for reporting the
device wakeup statistics.
Change the global wakeup events counters event_count and
events_in_progress into atomic variables, so that it is not necessary
to acquire a global spinlock in pm_wakeup_event(), pm_stay_awake()
and pm_relax(), which should allow us to avoid lock contention in
these functions on SMP systems with many wakeup devices.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
In order for PowerTOP to be able to report how well the new runtime PM is
working for the various drivers, the kernel needs to export some basic
statistics in sysfs.
This patch adds two sysfs files in the runtime PM domain that expose the
total time a device has been active, and the time a device has been
suspended.
With this PowerTOP can compute the activity percentage
Active %age = 100 * (delta active) / (delta active + delta suspended)
and present the information to the user.
I've written the PowerTOP code (slated for version 1.12) already, and the
output looks like this:
Runtime Device Power Management statistics
Active Device name
10.0% 06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller
[version 2: fix stat update bugs noticed by Alan Stern]
[version 3: rebase to -next and move the sysfs declaration]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1361) changes the runtime PM interface slightly; it
allows suspend requests to be scheduled while the runtime_suspend
method is running. If the method succeeds then the scheduled request
is cancelled, whereas if the method fails then an idle notification is
sent only if no request was scheduled.
Being able to schedule suspend requests from within a runtime_suspend
method is useful for drivers that need to test for idleness and
suspend the device all while holding a single spinlock, or for drivers
that want to check for idleness by polling.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Add new device sysfs attribute, power/control, allowing the user
space to block the run-time power management of the devices. If this
attribute is set to "on", the driver of the device won't be able to power
manage it at run time (without breaking the rules) and the device will
always be in the full power state (except when the entire system goes
into a sleep state).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
The power management of some devices is handled through device types
and device classes rather than through bus types. Since these
devices may also benefit from using the run-time power management
core, extend it so that the device type and device class run-time PM
callbacks can be taken into consideration by it if the bus type
callback is not defined.
Update the run-time PM core documentation to reflect this change.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1308c) fixes __pm_runtime_get(). Currently the routine
will resume a device if the prior usage count was 0. But this isn't
right; thanks to pm_runtime_get_noresume() the usage count can be
positive even while the device is suspended.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The runtime PM core code assumes that dev->power.timer_expires is
nonzero when the timer is scheduled, but it may become zero
incidentally in pm_schedule_suspend(). Prevent this from happening
by bumping dev->power.timer_expires up to 1 if it's 0 before calling
mod_timer().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
This patch (as1307) adds a small optimization to
__pm_request_resume(). If the device is currently being suspended,
there's no need to queue a work routine to resume it. Setting the
deferred_resume flag will suffice. (There's also a minor improvement
to the function's code layout: An unnecessary "else" is removed.)
Also, the patch clarifies the usage of the deferred_resume flag. It
is meaningful only while a suspend is in progress, so it should be
cleared just before a suspend starts, not just after one ends.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Lockdep complains about taking the parent lock in
__pm_runtime_set_status(), so mark it as nested.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@kernel.org
This patch (as1305) fixes a bug in the irq-enable settings and removes
some related overhead in the runtime PM code.
In __pm_runtime_resume(), within the scope of the original
spin_lock_irq(), we know that irqs are disabled. There's no
reason to go through a pair of enable/disable cycles when
acquiring and releasing the parent's lock.
In __pm_runtime_set_status(), irqs are already disabled when
the parent's lock is acquired, and they must remain disabled
when it is released.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Introduce a core framework for run-time power management of I/O
devices. Add device run-time PM fields to 'struct dev_pm_info'
and device run-time PM callbacks to 'struct dev_pm_ops'. Introduce
a run-time PM workqueue and define some device run-time PM helper
functions at the core level. Document all these things.
Special thanks to Alan Stern for his help with the design and
multiple detailed reviews of the pereceding versions of this patch
and to Magnus Damm for testing feedback.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@igel.co.jp>
This patch (as933) removes the deprecated dpm_runtime_suspend() and
dpm_runtime_resume() routines from the PM core. The only user of
those routines is the PCMCIA ds driver; local replacements are added.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The Power Management code uses semaphores as mutexes. Use the mutex API
instead of the (binary) semaphores.
Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Merge the suspend and resume methods for 16-bit PCMCIA cards into the
device model -- for both runtime power management and suspend to ram/disk.
Bugfix in ds.c by Richard Purdie
Signed-Off-By: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
This patch #if 0's an unused global function.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch collects various small updates related to root hubs, to shrink
later patches which build on them.
- For root hub suspend/resume support:
* Make the existing usb_hcd_resume_root_hub() routine respect pmcore
locking, exporting and using the dpm_runtime_resume() method.
* Add a new usb_hcd_suspend_root_hub() to pair with that routine.
(Essential to make OHCI autosuspend behave again...)
* HC_SUSPENDED by itself only refers to the root hub's downstream ports.
So let HCDs see root hub URBs unless the parent device is suspended.
- Remove an assertion we no longer need (and now, also don't want).
- Generic suspend/resume updates to work better with swsusp.
* Ignore the FREEZE vs SUSPEND distinction for hardware; trying to
use it breaks the swsusp snapshots it's supposed to help (sigh).
* On resume, mark devices as resumed right away, but then
do nothing else if the device is marked NOTATTACHED.
These changes shouldn't be very noticable by themselves.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/base/power/runtime.c | 1
drivers/usb/core/hcd.c | 64 ++++++++++++++++++++++++++++++++++++++-----
drivers/usb/core/hcd.h | 1
drivers/usb/core/hub.c | 45 ++++++++++++++++++++++++------
drivers/usb/core/usb.c | 20 +++++++++----
drivers/usb/core/usb.h | 1
6 files changed, 111 insertions(+), 21 deletions(-)
This adds type-checking to pm_message_t, so that people can't confuse it
with int or u32. It also allows us to fix "disk yoyo" during suspend (disk
spinning down/up/down).
[We've tried that before; since that cpufreq problems were fixed and I've
tried make allyes config and fixed resulting damage.]
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Alexander Nyberg <alexn@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Ingo Molnar
Rafael J. Wysocki
Linus Torvalds
Tony Lindgren
Ulf Hansson
Paul E. McKenney
Linus Walleij
Andrzej Hajda
Geert Uytterhoeven
Ming Lei
Kevin Hilman
Rafael J. Wysocki
Alan Stern
venu byravarasu
Paul Gortmaker
Colin Cross
ShuoX Liu
Lucas De Marchi
Kevin Winchester
Ming Lei
Arjan van de Ven
Pavel Machek
Matthias Kaehlcke
Dominik Brodowski
Adrian Bunk
David Brownell
Linus Torvalds